Clutch



Sept. 26, 1944. w 5 WQLFRAM 2,359,184

CLUTCH Filed May 29, 1942 2 Sheets-Sheet l L: a: .M /1 'IlV Clttornegs Sept. 26, 1944. w. s, woLFRAM CLUTCH Filed May 29, 1942 2 Sheets-Sheet 2 (Ittornegs patented Sept. 26, i944 CLUTCH William S. Wolfram, Scotch Plains,

to General Motors Corporation,

N. J., assigner Detroit, Mich.,

a corporation of Delaware Application May 29, 1942, Serial No. 445,035

2 Claims.

This invention relates to friction clutches, such as are used on motor vehicles to couple the engine and transmission shafts.

It is an object of this invention to overcome chatter, resulting from an irregular clutch engaging action. i

Among other objects are the accomplishment of the major object by means which shall be eiective and yet simple and inexpensive.

vOn the drawings which show several embodiments:

Fig. 1 is a. transverse section, the section being marked on Fig. 2 by line I-I. f

Fig. 2 is a view of this form in elevation.

Fig. 3 is a partial section of a second form, the section being on line 3-3 of Fie'. 4.

Fig. i is a view in elevation of this second form.

Fig. 5 and Fig. 6 are views in section and elevation respectively of a third form.

Figs. 'l' and 8 are views in section and elevation respectively oi a fourth form.

Prior to the present invention eiiorts have been made to improve the engagement oi the friction. members oi vehicle clutches. These eiiorts have frequently involved modifications of the driven plate, such as the formation of tongues in that part of the driven plate between its facings and normally bent from the plane of the plate so that they oier resilient resistance as they are forced into the plane of the plate as the clutch members come into engagement under the influence of the clutch engaging spring.

The present invention has a somewhat similar object. Its several forms have in common the use of the clutch cover to provide the resilient cushioning action.

On Fig. 1 is shown an engine shaft Il and transmission shaft I3. The engine shaft carries the ywheel I5. To house the friction members is a cover H. It is secured to the flywheel at I9.

Within the cover will be seen the driven plate having a hub 2| slidably splined on shaft i3. The hub carries a plate 23 with friction facings 25. A pressure plate 21 is arranged with radially extending lugs 29 projecting through axially elongated openings 3i in the cover. It may slide axially and when moved forward to grip the driven plate it may transmit thereto the rotation of the flywheel and cover since, because of lugs 29, it must rotate with the cover. At 93 is a baille to keep oil from the facings.

The cover supports a circular series of pins 3lupon which are rings 31, l1' between which rings is the radially slotted bowed clutch engaging Aspring 39, the spring having openings to receive the pins. Spring 39 is stressed in assembly so that its marginal region 4I presses the pressure plate forwardly to clutch engaging position and ring 31 takes the reaction, transmitting it to the cover. To release the clutch some suitable throwout means such as a collar 43 is pushed Iorward upon the central part oi.' the spring. This takes the load from ring 31. 'I'he spring fulcrums as it were about ring 37. 'I'he load on the pressure plate is relieved and as the marginal portion of the spring moves tothe right (Fig. l) suitable expediente such as lingers 45 secured at 41 to the pressure plate and overlying the edge of the spring positively move the pressure plate to inoperative position.

As has been stated above, expedients have been adopted to offer resilient resistance to the movement oi the pressure plate under the influence of springs such as spring 39. In the embodiments herein shown the cover plate is used to furnish the resilient action. As the clutch reengages after release the reaction at ring 3l and the' cover corresponds to the increasing pressure on the flywheel. The inventive idea consists in constructing the cover' to yield under the influence of the reaction and thus retard the active force at 4i.

In Fig. l. it will be seen that the cover is of that kind having a circular bowed region at 49. In this region 49 there are provided a series of openings 5| which render the cover somewhat resilient, suillciently resilient so that, as the spring 39 presses plate 21, the reaction at 31' is resisted not by a rigid cover but a cover which yields to some extent and thereby smooths out the clutch engaging action. Of course itis self-evident that with my invention there may be used any of the known forms of axially cushioning driven plate structures but it is believed that my resilient cover may be sufllcient to afford the smooth clutch engagement without resort to these older expedients.

In Figs. 3 and 4 is shown a very simple structure of cover which may be used to carry out the object of the invention. In this form cover Il' is used instead of cover i1. The other parts of the clutch may be the same and need not be described. This cover lacks the bowed region 49 of cover- Il, being fiat in the region where cover i'l was bowed. Also it will 'be seen that the axial flange Ill of cover i1 is omitted. The omission of the bowed region and the axial flange will, it is believed, enable this cover with its flat rear face to afford the resiliency necessary to get the smooth clutch engagement.

In Figs. 5 and 6 the parts of the clutch except for the cover are the same as in Fig. 1 and they have been given the same reference characters. The cover of Fig. 5 is marked Il". It has, as in the other ilgures, an annular ringportion between the rear face and the attaching ilange. Its rear face, the spring abutment wall, is changed. Deep tapered scallop-shaped iormations 5| extend radially outward from the innermost part of the cover.V These formationsleave triangular tongues 53 with apices directed to the clutch centerz" These tongues 53 carry the ring supportbetween the radially outward wider region and their inner apices which carry the pins and thusA furnish the axial cushioning.

In Figures 'I and 8 the inventive idea is .shown associated with a somewhat different form of clutch. This clutch has a ilywheel 55 to which is secured at 51 a cover 59. Within the cover springs such as 6l press the pressure plate B3 toward the flywheel to grip the usual driven plate 65. Any convenient throwout means may be used to overcome springs 6l and withdraw the pressure plate. This is no part of the invention and need not be described. 'I'he cover has a relatively wide ilange B1 and the attaching means are at its outer margin with the result that the annulus outwardly of the circular junction at 59 between of course quickly builds up so that spring 5I acts as if against a rigid cover.

Although shown with a clutch having coil springs it will be appreciated that the same form members. spring means to press said members together, a clutch cover in the form of a peripheral circular wall attached to one o! said members and with a circular series oi' triangular formations having bases integral with said circular wall and with inwardly directed apices, said apices determining an inner circle concentric with said circular wall and abutment means for said spring means carried by said apices.

2. In a clutch having Irictionally engaging members, spring means to press said members together. a clutch cover having a. wall in the form of a circular series of triangular formations with their apices toward the center, means on and adjacent the apices oi said formations to take the reaction of said spring means, said spring means being a bowed disc and said last named means comprising a plurality of pins and a ring supported thereby between said formations and the ilange 61 and the annular ring portion may yield A30 'bowed disc.

and oier resistance to clutch engagement under the influence of spring 6I. The resiliency WILLIAM S. WOLFRAM. 

